These are two of several magnesium mold samples in the Museum’s collection. Acquired in 1939 for the exhibit Uses of Magnesium Metal, the samples illustrate the expanding industrial uses of magnesium and the manufacturing techniques that helped establish it as an important modern engineering material. In mold casting, molten magnesium is injected under high pressure into a mold, allowing complex, precisely shaped parts to be produced rapidly and consistently. Extrusion is a separate process in which magnesium is forced through a shaped opening to create a continuous form that can later be cut or machined.

Magnesium’s light weight and high strength-to-weight ratio made it increasingly important to 20th-century manufacturing. Approximately 75 percent lighter than steel and 33 percent lighter than aluminum, it became especially useful in applications where reducing weight was critical. Its properties eventually supported advances in the automotive, medical, electronics, and aerospace industries.